1. Field of the Invention
The present invention relates to power supplying technology and more particularly, to a low-loss data transmission method for high-power induction-type power supply system, which allows for transmission of power supply and data signal at the same time, assuring a high level of stability of the supplying of power supply and reducing energy dissipation of signal transmission.
2. Description of the Related Art
Following fast development of electronic and internet technology, many digitalized electronic products, such as digital camera, cellular telephone, multimedia player (MP3, MP4) and etc., have been continuously developed and have appeared on the market. These modern digital electronic products commonly have light, thin, short and small characteristics. However, for high mobility, power supply is an important factor. A mobile digital electronic product generally uses a rechargeable battery to provide the necessary working voltage. When power is low, the rechargeable battery can be recharged. For charging the rechargeable battery of a digital electronic product, a battery charger shall be used. However, it is not economic to purchase a respective battery charger when buying a new mobile electronic product. Further, when one spends a big amount of money to purchase different mobile electronic products, a special storage space is necessary for the storage of the mobile electronic products. Further, it is inconvenient to carry and store many different mobile electronic products and the related battery chargers.
Further, when using a battery charger to charge a mobile electronic apparatus, the user must connect the connection interface (plug) of the battery charger to an electric outlet and then connect the connector at the other end of the battery charger to the mobile electronic apparatus, enabling the mobile electronic apparatus to be charged. After charging, the mobile electronic apparatus is disconnected from the battery charger. As conventional battery chargers can be used in a place where an electric outlet is available, the application of conventional battery chargers is limited. When in an outdoor space, conventional battery chargers cannot be used for charging mobile electronic apparatuses.
Further, except battery charging, a mobile electronic apparatus may need to make setting of related functions, data editing or data transmission. A user may directly operate the mobile electronic apparatus to make function setting or to input data. However, some mobile electronic apparatus (such as MP3 player, MP4 player, digital camera, electronic watch, mobile game machine, wireless game grip, wireless controller) do not allow direct setting or data transmission. When making function setting or data transmission, an external electronic device (such as computer, PDA) must be used. Further, when charging a mobile electronic apparatus, it may be not operable to transmit data. Further, wireless induction power supply systems (or the so-called wireless chargers) are commercially available. These wireless induction power supply systems commonly use two coils, one for emitting power supply and the other for receiving power supply. However, the energy of wireless power supply is dangerous and will heat metal objects. They work like an electromagnetic stove. The use of a wireless induction power supply system has the risk of overheat damage of the charged device.
To overcome the problem conventional techniques that do not allow for transmission of data signal during charging, the applicant of the present invention invented a data transmission method for high-power induction-type power supply system. This invention was filed for patent on Feb. 1, 2011 under application number 100103836, and published on Jul. 1, 2011 under publication number 201123676. Subject induction between a supplying-end coil of a supplying-end module and a receiving-end coil of a receiving-end module, this method allows for transmission of power supply and data signal at the same time and has the characteristics of low energy dissipation, high data signal clarity and high fault tolerance. However, the modulation operation of the amplitude modulation circuit of the receiving-end module consumes a large amount of electric current. In actual wireless charging operation, this method has drawbacks as follows:
1. During signal modulation of the amplitude modulation circuit of the receiving-end module, a high voltage is obtained from the capacitor A3 of the resonant circuit and transmitted through a MOSFET component to the ground (GND). Because of high voltage, a large current is transmitted, causing significant energy dissipation at the coil and drop of waveform of the data signal decoded by the signal analysis circuit 13 (see the drop on the middle part of the waveform numbered by 3 in FIG. 12), and therefore the power receiving ability of the receiving-end module during this stage is weakened.
2. When the amplitude modulation circuit A1 of the receiving-end module A modulates a data signal (see FIG. 13), a large current of high voltage passes through the MOSFET component A11, and the MOSFET component A11 may be burned out by the large current of high voltage, shortening the lifespan of the receiving-end module A.
3. When the amplitude modulation circuit A1 of the receiving-end module A modulates a data signal, the rectifier A2 of the receiving-end module A provides a shortcut so that AC current can be directly transmitted to the receiving-end coil A4 without through the resonant circuit A3 (resonant capacitor), assuring high clarity of the feedback signal generated by the receiving-end coil A4. However, this condition causes a temporary interruption of power supply at the power loop behind the resonant circuit A3 when the receiving-end module A is modulating a data signal, resulting in instability of power output of the power output terminal A5 during the data signal modulation period.
The definitions of the reference numerals at the left side in FIG. 12 (please also refer to FIG. 13) are explained as follows:
#1: Control signal of N-type MOSFET component A11.
#2: Control signal of N-type MOSFET component A12.
#3: Output signal of signal analysis circuit.
#4: Signal of supplying-end microprocessor after interpretation.
Therefore, it is desirable to have a data transmission method for high-power induction-type power supply system that eliminates the problem of power supply interruption or loss during signal modulation operation of the amplitude modulation circuit of the receiving-end module of the aforesaid prior art design, and the problem of the conduction of a large current of high voltage to burn the MOSFET component during the signal modulation operation of the amplitude modulation circuit.